A known address printing machine of the type using embossed data carriers is described in German Pat. No. 24 57 114. Complicated driving mechanisms are used for moving the printing pad and the printing anvil into the operating position; i.e. there is provided either a toggle joint system, which absorbs the forces of impression when in an extended position, or a cam (rotating wedge) wich also causes the printing pad and the printing anvil to approach each other along an axis which is perpendicular to the printing pad or printing anvil plane, the cam acting against the force of a spring. Although this rotating wedge will ensure self-locking of the driving mechanism over a sufficient range, and thereby will accommodate various thicknesses of the printing assemblies in a relatively small range, this will be possible only in a complex and expensive structure.
It should be mentioned here, that from a small printing device of another type which primarily serves for imprinting with a credit card, see U.S. Pat. No. 4,085,675, it is already known to provide the central frame of the machine with a swivel arm, which however, comprises a printing roller which is caused by a drive motor to roll across the printing assembly when the swivel arm is in its lowered position. An electromagnetically operating locking mechanism is located between the central frame and the swivel arm the locking force of which decreases inversely proportional to the square of the thickness of the printing assembly.